A Big Step on the Road to Soft Machines

“The big vision is soft machines”

In a materials science laboratory at Harvard University, a transparent disk connected to a laptop fills the room with music—it’s the “Morning” prelude from Peer Gynt, played on an ionic speaker.

No ordinary speaker, it consists of a thin sheet of rubber sandwiched between two layers of a saltwater gel, and it’s as clear as a window. A high-voltage signal that runs across the surfaces and through the layers forces the rubber to rapidly contract and vibrate, producing sounds that span the entire audible spectrum, 20 hertz to 20 kilohertz (see video below).

But this is not an electronic device, nor has it ever been seen before. Published in the August 30 issue of Science, it represents the first demonstration that electrical charges carried by ions, rather than electrons, can be put to meaningful use in fast-moving, high-voltage devices.

For example, ionic conductors can be stretched to many times their normal area without an increase in resistivity—a problem common in stretchable electronic devices. Secondly, they can be transparent, making them well suited for optical applications. Thirdly, the gels used as electrolytes are biocompatible, so it would be relatively easy to incorporate ionic devices—such as artificial muscles or skin—into biological systems.

After all, signals carried by charged ions are the electricity of the human body, allowing neurons to share knowledge and spurring the heart to beat. Bioengineers would dearly love to mesh artificial organs and limbs with that system.

“The big vision is soft machines,” says co-lead author Christoph Keplinger, who worked on the project as a postdoctoral fellow at Harvard SEAS and in the Department of Chemistry and Chemical Biology. “Engineered ionic systems can achieve a lot of functions that our body has: they can sense, they can conduct a signal, and they can actuate movement. We’re really approaching the type of soft machine that biology has to offer.”

The audio speaker represents a robust proof of concept for ionic conductors because producing sounds across the entire audible spectrum requires both high voltage (to squeeze hard on the rubber layer) and high-speed actuation (to vibrate quickly)—two criteria which are important for applications but which would have ruled out the use of ionic conductors in the past.

The traditional constraints are well known: high voltages can set off electrochemical reactions in ionic materials, producing gases and burning up the materials. Ions are also much larger and heavier than electrons, so physically moving them through a circuit is typically slow. The system invented at Harvard overcomes both of these problems, opening up a vast number of potential applications including not just biomedical devices, but also fast-moving robotics and adaptive optics.

May 24, 2018 - Since complex problems are often solved with many intelligences (human and machine), universities must overcome the dated industrial age bias against teaching the so-called “soft skills” of teamwork and collaboration. Educational institutions should ...

May 24, 2018 - “If we want to build machines that are more compatible with the human body and the natural environment, we have to start with new types of materials,” said Carmel Majidi, an engineer at Carnegie Mellon University who directs the Integrated Soft ...

May 23, 2018 - Can we expect Halo Top soft serve oozing out of machines permanently in NYC? A publicist told us, "In terms of Halo Top bringing a scoop shop [there are two in L.A.] to the East Coast, there's a possibility in the future but there are no set plans just ...

May 23, 2018 - Today, it is easy to envision a world in which humans and robots collaborate -- in close proximity -- in many realms. Emerging soft robots may help to ensure that this can be done safely, and in a way that syncs to human environments or even interfaces ...

May 22, 2018 - “The first thing I do every morning is I taste the ice cream,” said Mr. Vasquez, filling up the hoppers of his soft-serve machine with chocolate and vanilla mix. “I make sure the ice cream is good.” Good: A light, airy, melt-away texture that can ...

Since complex problems are often solved with many intelligences (human and machine), universities must overcome the dated industrial age bias against teaching the so-called “soft skills” of teamwork and collaboration. Educational institutions should ... […]

with the classification of soft or inflexible becoming irrelevant in the next generation of structures and machines. The structure itself is simple enough, with layers of flexible material that’s wrapped around a plastic envelope and then connected to a ... […]

On top of Peaches & Cream, they will also be offering Peanut Butter Cup and Vanilla Bean. Can we expect Halo Top soft serve oozing out of machines permanently in NYC? A publicist told us, "In terms of Halo Top bringing a scoop shop [there are two in L.A ... […]

KINGSTAR, the industry’s most innovative and complete motion control platform, today announced the launch of the KINGSTAR Soft Motion Platform to the ... hardware and individual solutions for industrial machine automation. Through pre-tested, pre ... […]

... name inspired by the machines that dispense candy and soft drinks. In the case of Facebook’s Vending Machine, the input is a device role, location, and platform, and out pops a freshly provisioned network device, ready to deliver production traffic.&rdquo […]

“If we want to build machines that are more compatible with the human body ... Many engineers believe that soft electronics will help revolutionize the way robots function, and also how they’re perceived in society. Flexible and durable machinery ... […]

In the world of robotics, soft robots are the new kids on the block. The unique capabilities of these automata are to bend, deform, stretch, twist or squeeze in all the ways that conventional rigid robots cannot. Today, it is easy to envision a world in ... […]

Soft and tactile machines are the direct opposite of what you’d expect from machines but this wasn’t it… I realised that it was feeling something physical from watching. This (it turns out) is down to a phenomenon called synaesthesia. It was this ... […]

Stoelting’s C111-37 Soft Serve Countertop Freezer is designed for professional foodservice operations. Unit comes with 1.6 gal capacity and cup sensor prepares the machine to serve and shorten the delay of dispensing. Freezer can be used on both ... […]